标题：Conditional and inducible transgene expression in endothelial and hematopoietic cells using Cre/loxP and tetracycline-off systems
作者：Liu, Ju;Deutsch, Urban;Fung, Iris;Lobe, Corrinne G.
作者机构：[Liu, J] Laboratory of Microvascular Medicine, Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 更多
通讯作者地址：[Liu, J]Shandong Univ, Shandong Prov Qianfoshan Hosp, Med Res Ctr, Lab Microvasc Med, 16766 Jingshi Rd, Jinan 250014, Shandong, Peoples R China.
来源：Experimental and therapeutic medicine
关键词：Cre/loxP system;tetracycline;endothelial cells;hematopoietic cell;transgenic mice
摘要：In the present study, the tetracycline-off and Cre/loxP systems were combined to gain temporal and spatial control of transgene expression. Mice were generated that carried three transgenes: Tie2-tTA, tet-O-Cre and either the ZEG or ZAP reporter. Tie2-tTA directs expression of tetracycline-controlled transactivator (tTA) in endothelial and hematopoietic cells under the control of the Tie2 promoter. Tet-O-Cre produces Cre recombinase from a minimal promoter containing the tet-operator (tetO). ZEG or ZAP contains a strong promoter and a loxP-flanked stop sequence, followed by an enhanced green fluorescence protein (EGFP) or human placental alkaline phosphatase (hPLAP) reporter. In the presence of tetracycline, the tTA transactivator produced by Tie-2-tTA is disabled and Cre is not expressed. In the absence of tetracycline, the tTA binds tet-O-Cre to drive the expression of Cre, which recombines the loxP sites of the ZEG or ZAP transgene and results in reporter gene expression. In the present study, the expression of the ZEG or ZAP reporter genes in embryos and adult animals With and without tetracycline treatment was examined. In the presence of tetracycline, no reporter gene expression was observed. When tetracycline was withdrawn, Cre excision was activated and the reporter genes were detected in endothelial and hematopoietic. cells. These results demonstrate that this system may be used to bypass embryonic lethality and access adult phenotypes.